Do We Really Need The Moon?

That is the title question of a 2011 hour long documentary co-produced by BBC Worldwide and Discovery. Hosted by space scientist  Dr. Maggie Aderin-Pocock, and using state of the art CGI effects, the film explores why the Moon is necessary, and why it is so important to our planet.
.
In the search for answers, Aderin-Pocock travels across the US, UK, and Bahamas speaking with other space scientists, chemists, astronomers, and even the police.  She investigates how the moon was formed, and what would happen to life on Earth, and Earth itself, if the Moon were closer or further away.

Aderin-Pocock has had a life long obsession with the Moon; all she's wanted to do since discovering science is to study it. This excitement really comes through.

In reality, it is amazing how much the Moon affects our lives and planet. Take the tides, for instance. The tides are because of the Moon's gravitational pull on Earth.

Think of a 10g metal weight on a scale. The scale would naturally read 10 grams. Now, hold a magnet above the weight. The scale would read less than 10 grams because of the attraction the magnet has toward the weight. Similarly, the Moon (magnet) has a gravitational pull on the Earth (weight) which makes it slightly bulge. The oceans pull toward that end, and New England has high tide. Twelve hours later, the Earth and Moon have repositioned and now London has high tide.

And this works for us, everything is fine. But what if the Moon were 20 times closer? The gravitational effect would be 400 times stronger--and New York and London would be flooded during their respective high tides.

The Moon also has an effect on the length of our day. The length of our day is directly related to the distance from the Earth to the Moon, because the Moon has a "breaking effect" on the planet--the faster the Earth spins, the shorter our day is. Right now, as you know, the day is 24 hours long. But back in the Devonian Period, the Earth spun faster, and the day was 21 1/2 hours long.

But let's say the Moon is 10% further away. What would happen then? For one thing, the Earth would tip on its side. The planet is currently tilted at a stable 23 degrees off its axis. If the Moon moved only a little further away, our 10%, the planet would become wobbly and tip right over. Sea levels would rise by as much as 60 meters. And Las Vegas would become a dark, cold, frozen wasteland in the winter; in the summer it would be extremely hot and the sun would never set.

And what do the cops have to do with any of this? Our host goes on a ride-along with the police to look into the myth that the full moon causes people to "go a little crazy". According to the film, there really isn't any evidence of this. But it did probably originate from the days before electric light--the full moon gives a brighter night sky, allowing people the chance to stay out later, and therefore have more opportunity to commit crime.(The logic makes sense to me, although I don't think criminals care what phase the moon is in.)

These are only a few of the questions answered in the film. But the bottom line is this: Do we really need the Moon? Yes. Yes, we do.